What Is a Grain Moisture Shrink Calculator?
When grain is dried down from harvest moisture to a safe storage moisture, it loses water weight — this is called "shrink." This calculator uses the standard grain-marketing shrink formula, the same method elevators use to convert wet weight to dry weight when they settle a load, so you know exactly how many bushels (and how much money) drying will cost you in weight.
Understanding shrink matters whether you're deciding when to sell wet corn versus drying it yourself, or just want to know how many dry bushels a bin of wet grain will actually yield.
How to Read Your Results
Shrink Percentage
This is the percentage of your wet weight that disappears as water during drying. It is not simply the difference in moisture points — because the remaining dry matter is the base of the calculation, the formula divides by (100 − target moisture) rather than by 100.
Dry Weight After Drying
Your wet weight multiplied by (1 − shrink%). This is the number of bushels you should actually expect once the grain reaches target moisture.
Bushels Lost to Shrink
The simple difference between your wet weight and dry weight — the bushels that "disappear" as moisture leaves the grain.
Value Lost to Shrink
If you entered a price per bushel, this multiplies the bushels lost by that price to show the dollar impact of drying, separate from any elevator drying charges.
Real-World Example
A farmer harvests 1,000 bushels of corn at 22% moisture and dries it to the standard 15% storage moisture, with corn priced at $4.20/bu.
| Item | Value |
|---|---|
| Shrink percentage | ≈8.24% |
| Dry weight | ≈917.6 bu |
| Bushels lost to shrink | ≈82.4 bu |
| Value lost to shrink | ≈$346 |
Even though moisture only dropped 7 points, shrink removes more than 8% of the bushels — a useful number to compare against elevator drying and shrink charges before deciding to dry on-farm instead.
Tips for Estimating Shrink
- Test moisture with a calibrated meter — small moisture errors compound into meaningful bushel differences at scale.
- Compare on-farm drying costs to elevator shrink and drying fees before choosing where to dry.
- Remember shrink accelerates near the target moisture — the last couple of points cost more bushels than the first couple.
- Recheck moisture after drying; over-drying below target also wastes bushels unnecessarily.
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Last updated: August 2026 · Reviewed by: Simple Calculator Tools Editorial Team